This invention relates to a folding box made of a boxboard (cardboard) such as a corrugated board, a thin synthetic resin street, or the like.
Most of conventional folding corrugated boxes have a bottom constituted by four portions which extend respectively from four side walls of the box, and can be folded and combined together. For folding the box, the four bottom portions are expanded, and are folded between the side walls.
Since the bottom of such a folding corrugated box comprises the four small portions extending respectively from the four side walls, the bottom is weak, and when the box holds a heavy article, the bottom is frequently broken or opened.
Furthermore, such a box can be easily deformed by a force applied obliquely thereto, and in such a case the four side walls are displaced with respect to one another, so that the box is twisted as a whole.
Furthermore, since the box is folded in such a manner that the side walls move toward each other, the box in a folded condition is rather long, and therefore the area of the folded box is rather large.